Most common benign bone tumour or osseous lesion covered by cartilage; M>F
Development dysplasia of peripheral growth plate forms cartilage capped projection of bone.
Palpated as a firm, nontender, immovable mass near end of long bones
X-ray – osseous protuberance with normal trabecular pattern
Subungual exostosis may develop on distal phalanx subungually – usually hallux. May have history of trauma. Treat with excision if painful – could debride nail thin and/or use tubular foam padding to keep shoe pressure off nail.